Memory: the capacity of the nervous system to acquire and retain usable skills and knowledge, allowing
organisms to benefit from the experience
Modal memory model: three stage system that involves sensory memory, short-term memory, and long
Sensory information, such as lights, smells and odors, leaves a trace on the nervous system for a split
second and then vanishes. This temporary sensory buffer is referred to as sensory memory. Visual
sensory memory is also called iconic memory; auditory sensory memory is also called echoic memory.
Iconic memory persisted for about 1/3 of a second, according to the grid of letters experiment.
Information that is attended to is passed from sensory stores to short term memory (STM), a limited-
capacity memory system that holds information in awareness for a brief period. Computer analogy =
Short term memory can hold information for no longer than about 20 seconds; it then disappears unless
you actively prevent that from happening by thinking about the information or rehearsing it. Example:
directory assistance- you repeat the phone number until you dial.
STM is generally limited to about seven items, plus or minus two, which is commonly referred to as
memory span. Memory span is limited to as most seven items, and probably fewer, but the items can be
letters, numbers, words, or even concepts. Second, meaningful units are easier to remember than
nonsense units. The process of organizing information into meaningful units is known as chunking.
Example- chess players are able to reconstruct a chess board by chunking the pieces into meaningful
STM is not a single storage system but rather an active processing unit that deals with multiple types of
information, such as sounds, images and ideas.
Working memory is an active processing system that keeps information available so that it can be used
for activities such as problem solving, reasoning, and comprehension. Three components of working
memory are central executive, phonological loop, visuospatial sketchpad.
Central executive presides over its interactions between subsystems and long-term memory. It encodes
information from the sensory systems and then filters information that is sufficiently important to be
stored in a long term memory. It also retrieves information from the long-term memory as needed.
Phonological loop encodes auditory information and is active whenever you read, speak, or repeat
words to yourself in order to remember them. Words are processed in working memory by how they
Visuospatial sketchpad processes visual information such as objects features and where they are
located. Example t you see a dog as you are walking. Visuospatial sketchpad helps you keep track of
where the dog is and if it is the type of dog that needs to be carefully tracked.